In order to combine a plurality of images together and to record the combined image on one sheet of paper, an information recording apparatus, such as disclosed in Japanese Examined Patent Publication No. 33752/1981 (Tokukoushou 56-33752), is employed. In this apparatus, image data for each page is stored as each independent data. For example, if image data of 4 pages of A-4 size are respectively stored as independent data, the information recording apparatus is capable of reducing the stored image data respectively and combining them together so as to form the combined image on one sheet of paper of A-4 size.
Here, in the case of applying the above-mentioned operation to an original document of a large size which cannot be read through one complete scanning, the image of the original document is read in a divided manner. These divided images are stored as divided image data including of a plurality of pages. However, in the above-mentioned apparatus, since the image data are stored as individual data for respective pages, there is no correlation between those individual data for respective pages. For this reason, even if the divided image data are reduced for the respective pages, and combined together, the divided images cannot be joined together into the original form.
Therefore, in the case of copying an original document having a size larger than, for example, the document platen on one sheet of paper of a desired size, the following method is used:
(1) An original document is divided into a plurality of regions, and those regions are respectively reduced and copied to form divided original documents; PA1 (2) The divided original documents are trimmed and pasted to form one sheet of original document; PA1 (3) The original document thus joined together is again copied. PA1 (1) an input means for reading an image of an original document; PA1 (2) a storage means for storing a plurality of partial images as respective partial document data, the partial images having been read by the input means in a divided manner; and PA1 (3) a joint-portion processing means for recognizing reference data in response to an output of the input means, the reference data providing a key by which joints of the partial document data that have been stored in the storage means are retrieved, for recognizing the joints using the recognized reference data as a key, and for positioning the respective partial document data in accordance with the recognized joints. PA1 (1) an input means for reading an image of an original document; PA1 (2) a storage means for storing a plurality of partial images as respective partial document data, the partial images having been read by the input means in a divided manner; and PA1 (3) a joint-portion processing means for obtaining specific image data containing features from the partial document data stored in the storage means by retrieving the partial document data stored in the storage means, and for selecting two partial document data in the order of their increasing number on the specific image data, comparing the specific image data each other, recognizing joints at which the specific image data coincide with each other, and positioning the respective partial document data in accordance with the recognized joints. With the above arrangement, the joint-portion processing means obtains the specific image data containing features from the partial document data by retrieving the partial document data stored in the storage means, and recognizes joints of the partial document data in the order of their increasing number on the specific image data obtained. In other words, the two partial document data, which have virtually the same amount of specific image data, have a high probability of coincident specific image data. Therefore by performing the recognition of specific image data in accordance with the above order, it becomes easier to find sides at which their specific image data coincide with each other even in the case where the sides contain few specific image data and it would be difficult to find joints from the sides. PA1 (1) an input means for reading an image of an original document; PA1 (2) a storage means for storing a plurality of partial images as respective partial document data, the partial images having been read by the input means in a divided manner; PA1 (3) a document-color recognition means for forming color data corresponding to the respective partial document data by recognizing the colors of the images read by the input means; and PA1 (1) an input means for reading an image of an original document; PA1 (2) a storage means for storing a plurality of partial images as respective partial document data, the partial images having been read by the input means in a divided manner; and PA1 (3) a joint-portion processing means for recognizing joints located between the partial document data stored in the storage means and for extracting image data that lie in a direction orthogonal to the joints of the partial document data and positioning the respective partial document data in accordance with the image data that lie in a direction orthogonal to the joints. PA1 (1) an input means for reading an image of an original document; PA1 (2) a storage means for storing a plurality of partial images as respective partial document data, the partial images having been read by the input means in a divided manner; PA1 (3) a black-document discrimination means for discriminating whether the partial document data in question stored in the storage means are mono-color document data or color document data; and PA1 (4) a joint-portion processing means for recognizing joints located between the partial document data stored in the storage means and for converting the color document data that have been discriminated by the black-document discriminating means into mono-color document data and positioning the respective partial document data in accordance with the converted mono-color document data. PA1 (1) an input means for reading an image of an original document; PA1 (2) a storage means for storing a plurality of partial images as respective partial document data, the partial images having been read by the input means in a divided manner; PA1 (3) a joint-portion processing means for recognizing joints located between the partial document data stored in the storage means, and for enhancing the image data so that the outlines of images located in the proximity of the joints are made distinct, and for positioning the respective partial document data in accordance with the enhanced image data.
However, in such a method including the above (1) through (3), troublesome and time consuming tasks are required in positioning and pasting the divided original documents manually, and in calculating a reduction rate in accordance with the size of copy sheet whereon a complete copied image is formed. Further, even if the reduction rate is set uniformly in obtaining the divided original documents, slight errors are inevitable in the reduction rates for the divided original documents. Therefore, offsets might be produced at the joints when those divided original documents are Joined together.
Meanwhile, Japanese Laid-Open Patent Publication No. 331567/1992 (Tokukaihei 4-331567) has disclosed a digital image forming apparatus wherein in the case of copying an original document that is larger than the copiable size, a plurality of image data that have been individually read are combined and compiled, and are reduced into a copiable size.
In this apparatus, if the copying operation is performed on an original document that is, for example, twice as large as the readable size, the original document is divided into two equal portions, and the portions are successively read. Then image data thus read are reduced, if necessary. In this case, upon reading the image data, the original document to be read later is placed on the document platen in a state where it is rotated by 180 degrees with respect to the original document that was read previously. Then, the image data that was read firstly is rotated by 90 degrees, while the image data that was read secondly is rotated by 90 degrees in the direction opposite to the first rotation, and both of the image data are combined together. Thus, a combined image is formed on one sheet of paper. Therefore, with such a digital image forming apparatus, the aforementioned troublesome and time consuming tasks are eliminated, and even in the case of copying an original document larger than the size of the document platen, a copied image is formed on one sheet of paper of a desired size.
However, in such an digital image forming apparatus, since the image data are merely reduced, and merely rotated in the predetermined directions, offsets might be produced at the joints in a combined image, thereby causing an adverse effect on picture quality. Further, in the case where divided original documents of an image come up to a number of pages, sufficient attention should be paid to the orientations of the original documents or to other factors when they are placed on the document platen. This raises a problem related to low efficiency in operation.